The decision comes in response to a Freedom of Information Act request submitted by CNN in December, after Tillerson had been announced as Trump's pick to lead the State Department, but before the inauguration and his subsequent confirmation by the Senate.
The request called for any "communications between ExxonMobil CEO/Chairman Rex Tillerson and officials at the State Department relating to Russia and US policy toward Russia."
In a response letter dated May 10, the State Department's FOIA office notified CNN it's search had yielded one document responsive to the request. "After reviewing the document, we have determined that it must be withheld in full," the letter states.
Tillerson had extensive dealings with the Russian government during his time at ExxonMobil, negotiating a partnership with the state-owned oil giant Rosneft.
The effort famously prompted Russia to award Tillerson the Order of Friendship, one of the highest honors Russia gives to foreign citizens.
In his confirmation hearing in January
, Tillerson acknowledged he "engaged" with the State Department, Treasury Department and Office of Foreign Asset Controls over US sanctions affecting an ExxonMobil project in the Russian arctic.
Tillerson said his outreach was designed "to explain to them there was significant risk to people and the environment" due to the way the sanctions were implemented, and to say his company would "comply with the sanctions, fully comply."
The State Department did not provide details on the content of the withheld document, except that it came from the Bureau of European and Eurasian Affairs, the regional bureau that implements US-Russia policies.
CNN submitted an appeal to the FOIA office Thursday over the decision to withhold the responsive document.
CNN has multiple pending FOIA requests related to Tillerson's communications with the State Department while at ExxonMobil.